On my Samsung CDRW/DVD SM-348B (T507) I can read and copy 3 of the files. One is reported with CRC errors. I try CD/DVD Diagnostic 2.02 (should work?) but does not do anything more than the standard Explorer copy and refuses to copy.

Now I try to play the avi file and it works to 99%. At the end av the clip a few frames are heavily pixelated, but thats all.

To rescue the clip I had to play it on one PC with video out (composite) and capture it with my capture card on another PC.

The disc is bad. This might be due to several factors. A prominent one is that you have scratched some part of it's lower surface or it has dirtiness on it due to incorrect user handling. Try cleaning it's lower surface with water and/or alcohol. Do not wipe it, or wipe it with a very soft and clean piece of clothe.

Generally I have found that most Sony CD-Rs are quite poor quality (see my review: Sony 48x CD-R Review).

The reason one drive performs better then the other is probably due to one drive having better error correction abilities then the other. Your Samsung Combo drive probably has a much higher C2 error tolerance then the BenQ DVD burner does.

The reason you can view the .avi's better then copy them is because when you are copying the files, you computer wants an exact replica of the original file, and will fail to copy if there is an unrecoverable error. When you play a movie, it has error coverup abilities (like when you play a scratched audio CD and you hear pops and clicks). This is what is happening when you see the pixilation. Using software like badcopypro might allow you to recover your files a little better, but it sounds like you've already done a pretty good job on that.

Thanks "Dolphinius_Rex" for your comment. Just one small comment. One of the reasons I went for the Benq DW800A was after reading the extensive test made at CDRInfo about its capabilities to read bad and scratched discs. Maybe my drive is a monday version! I will check with local dealer.

Well, I think there are differernces in correcting errors caused by dirt and/or scratches, and errors caused by a poor quality CD-R just in general not being good. Perhaps the BenQ DW800A is better at one type then the other... or maybe the Samsung is just an exceptional reader? it's hard to say, sorry.